JP2017194219A - Storage water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a storage water heater capable of suppressing gas consumption through maximum use of heat of hot water in a hot water storage tank as preheating for hot water supply.SOLUTION: A storage water heater includes: a hot water storage tank; a hot water supply passage connected to an upper portion of the hot water storage tank; a water supply passage connected to a lower portion of the hot water storage tank; and an auxiliary heat source machine interposed in the hot water supply passage. When a hot water temperature in the hot water storage tank is a hot water supply set temperature or lower, the hot water in the hot water supply passage is reheated by the auxiliary heat source machine. The storage water heater is configured so that a hot water delivery set temperature when the hot water is reheated by the auxiliary heat source machine and then delivered can be set on the basis of the hot water supply set temperature when the hot water supply set temperature is a predetermined reference temperature or higher and can be set on the basis of a water temperature in the water supply passage when the hot water supply set temperature is lower than the reference temperature.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hot water storage and hot water supply apparatus that stores hot water heated by an external heat source device in a hot water storage tank and can supply the stored hot water. The present invention relates to a hot water storage hot water supply device that can discharge hot water.

  Conventionally, hot water storage hot water storage devices with high energy efficiency that can store hot water heated by an external heat source device such as a heat pump water heater or a fuel cell in a hot water storage tank and supply the stored hot water to a hot water supply destination have been widely used. In recent years, further reduction of energy consumption for hot water supply is expected.

  Such a hot water storage hot water supply device supplies hot water even when all hot water stored at the hot water storage temperature stored in the hot water storage tank is discharged or when hot water of the hot water supply setting temperature cannot be discharged from the hot water storage tank due to the temperature drop of the stored hot water. For this purpose, the hot water in the hot water storage tank is heated by an auxiliary heat source machine and discharged. At this time, the hot and cold water heated to a predetermined hot water set temperature higher than the hot water set temperature is adjusted to the hot water set temperature by mixing with tap water and supplied to a hot water tap or the like.

  When the temperature difference between the hot water set temperature of the auxiliary heat source machine and the hot water temperature entering the auxiliary heat source machine is large, the auxiliary heat source machine is operated in the maximum combustion state and heated to the hot water set temperature by limiting the hot water flow rate of incoming water. It is controlled to be able to Therefore, since the hot water in the hot water storage tank is limited in the flow rate of water entering the auxiliary heat source machine, the heat of the hot water stored in the hot water storage tank is not used as the preheating for hot water supply, and the gas consumption is large. There is.

  On the other hand, although the hot water temperature of the hot water storage tank is not used as preheating for hot water supply, the can target temperature set by the applicant of the present application is set when the hot water supply set temperature is higher or lower than the control switching temperature. A different hot water supply apparatus is disclosed in Patent Document 1.

Japanese Patent No. 5200748

  However, even if the hot water supply device of Patent Document 1 is applied to the auxiliary heat source machine of the hot water storage hot water supply device, the heat of the hot water in the hot water storage tank cannot be used as the preheating of the hot water supply, and the gas consumption cannot be suppressed.

  An object of the present invention is to provide a hot water storage hot water supply apparatus capable of suppressing gas consumption by making maximum use of hot water of a hot water storage tank as preheating of hot water supply.

  The invention of claim 1 includes a hot water storage tank, a hot water supply passage connected to an upper portion of the hot water storage tank, a water supply passage connected to a lower portion of the hot water storage tank, and an auxiliary heat source unit interposed in the hot water supply passage. A hot water storage device configured to reheat hot water in the hot water supply passage with the auxiliary heat source device when the hot water temperature in the hot water storage tank is equal to or lower than a hot water supply set temperature, and is reheated by the auxiliary heat source device. The hot water set temperature when pouring hot water is set based on the hot water set temperature when the hot water set temperature is equal to or higher than a predetermined reference temperature, and when the hot water set temperature is lower than the reference temperature. It is configured to be settable based on the water temperature in the water supply passage.

  When the hot water supply set temperature is lower than the reference temperature in claim 1, the invention of claim 2 is based on the hot water set temperature set based on the water temperature in the water supply passage and the hot water set temperature. A comparison is made with the set hot water set temperature, and the hot water set temperature is set at a low temperature.

  According to the invention of claim 1, when the hot water supply set temperature is equal to or higher than the reference temperature, the hot water set temperature is set based on the hot water set temperature, and when the hot water set temperature is lower than the reference temperature, the hot water set temperature is set to the water supply passage. Since the hot water set temperature is lower than the reference temperature, the hot water set temperature can be set low because the hot water set temperature is lower than the reference temperature. As a result, hot water in the hot water storage tank can be supplied to the external heat source machine as much as possible, and the heat stored in the hot water in the hot water storage tank is used for heating in the external heat source machine as a preheating of hot water to reduce gas consumption. In addition, the amount of clean water to be mixed to adjust to the hot water supply set temperature becomes small, and the hot water in the hot water storage tank can be used for maximum hot water supply.

  According to the invention of claim 2, when the hot water supply set temperature is lower than the reference temperature, the hot water set temperature based on the hot water set temperature is compared with the hot water set temperature based on the water temperature in the water supply passage, and the lower one is set as the hot water set. Since it was comprised so that it might be set as temperature, the hot water set temperature can be set low. As a result, hot water in the hot water storage tank can be supplied to the external heat source machine as much as possible, and the heat stored in the hot water in the hot water storage tank is used for heating in the external heat source machine as a preheating of hot water to reduce gas consumption. In addition, the amount of clean water to be mixed to adjust to the hot water supply set temperature becomes small, and the hot water in the hot water storage tank can be used for maximum hot water supply.

It is a schematic block diagram of the hot water storage hot-water supply apparatus of this invention. It is a figure which shows the hot water supply operation which supplies hot water stored in the hot water storage tank. It is a figure which shows the hot water supply operation which heats hot water with an auxiliary heat source machine, and supplies hot water.

  Hereinafter, modes for carrying out the present invention will be described based on examples.

Initially, the schematic structure of the hot water storage hot-water supply apparatus 1 of this invention is demonstrated.
As shown in FIG. 1, a hot water storage hot water supply apparatus 1 includes a hot water storage hot water supply unit 2 and an external heat source unit 3. The hot water storage and hot water supply unit 2 branches from the hot water storage tank 5, the hot water supply passage 6, the tank hot water supply passage 7 connecting the upper end of the hot water storage tank 5 and the hot water supply passage 6, and the tank hot water supply passage 7, via the auxiliary heat source unit 4. An auxiliary heating passage 8 connected to the hot water supply passage 6, a heating circulation passage 9 connecting the hot water storage tank 5 and the external heat source unit 3, a water supply passage 10 for supplying clean water to the hot water storage hot water supply unit 2, and a control unit for performing various controls 11 etc.

Next, the hot water storage tank 5 will be described.
The hot water storage tank 5 stores hot water heated by the external heat source unit 3. On the outer periphery of the hot water storage tank 5, a plurality of temperature sensors 5a to 5d are provided in order from the bottom in order to detect the temperature of the stored hot water. The position and number of temperature sensors provided in the hot water storage tank 5 can be appropriately changed according to the specifications of the hot water storage hot water supply apparatus 1 and the like. Moreover, although illustration is abbreviate | omitted, in order to prevent the temperature fall of the stored hot water, the circumference | surroundings of the hot water storage tank 5 are covered with the heat insulating material.

Next, the heating circulation passage 9 will be described.
The heating circulation passage 9 connects the lower end portion of the hot water storage tank 5 to the external heat source device 3 and connects the heating circulation passage portion 9a having the circulation pump 13 to the upper end portion of the external heat source device 3 and the hot water storage tank 5 to circulate 14 has a heating circulation passage portion 9b. Between the heating circulation passage portions 9a and 9b, a bypass passage portion 9c branched from the heating circulation passage portion 9b and connected to the circulation switching valve 15 provided in the heating circulation passage portion 9a is provided. The circulation switching valve 15 can switch the hot water flow path to the bypass passage side or the hot water storage tank side.

  During the hot water storage operation, the circulation switching valve 15 is set to the hot water storage tank side in the heating circulation passage 9 to operate the circulation pump 13, and the hot water in the lower part of the hot water storage tank 5 is heated to the hot water storage set temperature by the external heat source unit 3. Is stored in the upper part of the hot water storage tank 5. Only in special cases such as when the hot water cannot be heated to the hot water storage set temperature, the hot water heated by the external heat source unit 3 can be sent to the external heat source unit 3 and reheated by switching the circulation switching valve 15 to the bypass passage side. ing.

Next, the water supply passage 10 will be described.
The water supply passage 10 supplies the hot water supplied from the hot water source to the hot water storage hot water supply unit 2, and has an upstream end connected to the hot water source and a downstream end connected to the lower end of the hot water storage tank 5. A water supply bypass passage 18 is branched from the water supply passage 10 and connected to the mixing valve 16. The water supply passage 10 is provided with a water supply temperature sensor 19 and a check valve 20 for detecting the water temperature in the water supply passage 10 (hereinafter also referred to as water supply temperature), and the water supply bypass passage 18 is provided with a check valve 21. Yes. The high temperature hot water avoidance passage 22 branched from the water supply bypass passage 18 and connected to the hot water supply passage 6 is configured to avoid high temperature hot water unexpected by the user.

Next, the hot water supply passage 6 and the tank hot water supply passage 7 will be described.
The hot water supply passage 6 supplies hot water having a hot water supply set temperature to the bathtub 29, a hot water tap (not shown), and the like, and has an upstream end connected to the mixing valve 16. The tank outlet passage 7 supplies hot water stored in the hot water storage tank 5 to the hot water supply passage 6 and connects the upper end of the hot water storage tank 5 to the mixing valve 16. The branch passage 6 a branched from the hot water supply passage 6 includes an on-off valve 31 and can supply hot water to the bathtub 29. The hot water supply set temperature can be set to a temperature within a predetermined range by the user operating the operation remote controller 40.

  The mixing valve 16 adjusts the mixing ratio between the low temperature clean water supplied from the water supply bypass passage 18 and the high temperature hot water supplied from the tank outlet passage 7, and the hot water adjusted to the hot water supply set temperature is supplied to the hot water supply passage 6. Supply. Hot water having a hot water supply set temperature is supplied from the hot water supply passage 6 to a hot water tap or the like. A hot water supply temperature sensor 23 is provided in the hot water supply passage 6 to detect the hot water supply temperature.

Next, the auxiliary heating passage 8 will be described.
The auxiliary heating passage 8 includes an upstream auxiliary heating passage portion 8a branched from the tank outlet passage 7 and connected to the three-way valve 17, and an auxiliary heating passage portion 8b having the pump 25 connected to the three-way valve 17 and the auxiliary heat source unit 4. The auxiliary heat source unit 4 is connected to the downstream side of the branch of the upstream auxiliary heating passage 8a of the tank outlet 7 and the auxiliary heating passage 8c having a water proportional valve 26 and an auxiliary heat source outlet temperature sensor 27 is provided. Have.

Next, the auxiliary heat source unit 4 will be described.
The auxiliary heat source unit 4 is composed of a known gas water heater with a built-in heat exchanger or burner (not shown), and only in special cases such as when there is no hot water in the hot water storage tank 5 above the hot water supply set temperature during the hot water supply operation. Then, the combustion operation is performed according to a command from the control unit 11 to heat the hot water to the hot water set temperature.

  When the auxiliary heat source machine hot water is used to discharge hot water heated by the auxiliary heat source apparatus 4, the pump 25 and the auxiliary heat source apparatus 4 are operated and the water proportional valve 26 is opened. Then, the hot water in the hot water storage tank 5 enters the auxiliary heat source device 4 through the upstream auxiliary heating passage portion 8a, the three-way valve 17 and the auxiliary heating passage portion 8b, and is heated to the hot water set temperature by the auxiliary heat source device 4. Hot water discharged from the auxiliary heat source unit 4 enters the mixing valve 16 through the auxiliary heating passage 8c and the tank outlet passage 7, is adjusted to the hot water supply set temperature by the mixing valve 16, and is supplied to the hot water supply destination.

Next, the heat exchanger 12 and the tracking passage 28 will be described.
The heat exchanger 12 performs heat exchange between the hot hot water flowing through the heat exchanger forward passage portion 32a branched from the downstream auxiliary heating passage portion 8c and the low temperature hot water of the bathtub 29 circulating through the memorial passage 28, Hot water in the bathtub 29 is heated. The memorial passage 28 includes a passage passage portion 28 a that sends hot water heated by the heat exchanger 12 to the bathtub 29, and a bath return passage portion 28 b that includes a bathtub pump 30 that sends hot water from the bathtub 29 to the heat exchanger 12. Have.

  The downstream end of the heat exchanger return passage portion 32b on the outlet side of the heat exchanger 12 is connected to the three-way valve 17, and the branch passage portion 10a branched from the water supply passage 10 is connected to the heat exchanger return passage portion 32b so that water can be supplied. Has been. A heat exchanger electromagnetic valve 33 is provided in the heat exchanger return passage 32b.

Next, the external heat source unit 3 will be described.
The external heat source unit 3 is controlled by the control unit 11 via the auxiliary control unit 34, and the compressor 35, the condensation heat exchanger 36, the expansion valve 37, and the evaporating heat exchanger 38 are connected by the refrigerant pipe 39 to connect the heat pump circuit. The heat pump hot water supply apparatus is configured to heat hot water using heat of the refrigerant and the outside air enclosed in the refrigerant pipe 39. The external heat source unit 3 is not limited to a heat pump hot water supply device, and may be a hot water supply device that uses exhaust heat of a fuel cell.

Next, the control unit 11 will be described.
The control unit 11 acquires the hot water temperature of each part by the hot water storage temperature sensors 5a to 5d, the circulation temperature sensor 14, the feed water temperature sensor 19, the hot water temperature sensor 23, etc., operates the mixing valve 16 and the circulation pump 13, etc. The heat source operation 3 and the auxiliary heat source device 4 are operated to control the hot water storage operation, the hot water supply operation, and the like so that the hot water supply temperature set by the operation remote controller 40 can be supplied.

Next, hot water storage operation will be described.
The control unit 11 operates the external heat source unit 3, switches the circulation switching valve 15 to the hot water storage tank side, operates the circulation pump 13, and supplies hot water at a feed water temperature from the lower part of the hot water storage tank 5 to the external heat source unit 3. Hot water at a set temperature of hot water heated by the external heat source unit 3 is stored in the upper part of the hot water storage tank 5. By continuing the hot water storage operation, the hot water layer of hot water set temperature stored in the upper part of the hot water storage tank 5 expands downward, and the hot water layer of hot water temperature decreases. In addition, a medium temperature water layer having a temperature gradient that changes from the stored hot water set temperature to the feed water temperature by diffusion or heat conduction is formed between the hot water layer at the hot water set temperature and the hot water layer at the feed water temperature. The control unit 11 can detect the amount of hot water at the hot water storage set temperature in the hot water storage tank 5 based on the temperatures detected by the plurality of temperature sensors 5 a to 5 d provided in the hot water storage tank 5.

Next, the hot water supply operation will be described.
As shown in FIG. 2, when the hot water supply operation is started, low temperature clean water flows into the hot water storage tank 5 from the lower end portion of the hot water storage tank 5 through the water supply passage 10, and the upper end portion of the hot water storage tank 5 by this water supply pressure. From the hot water storage set temperature flows into the mixing valve 16 through the tank hot water outlet passage 7. The control unit 11 adjusts the mixing valve 16 to supply hot water at a hot water supply set temperature from the hot water supply passage 6.

  When the hot water supply is continued, the low-temperature hot water layer below the hot water storage tank 5 expands upward, the intermediate-temperature water layer moves upward, and the hot water layer at the hot water storage set temperature decreases. When the uppermost hot water storage temperature sensor 5d detects a temperature lower than the hot water supply set temperature of the medium hot water layer, the three-way valve 17 is switched to the hot water storage tank side, the pump 25 and the auxiliary heat source unit 4 are operated, The proportional valve 26 is opened and the auxiliary heat source machine hot water is started.

  When the hot water supply set temperature is equal to or higher than a predetermined reference temperature (for example, 40 ° C.), the hot water set temperature of the auxiliary heat source device 4 is set to a temperature that is higher by a predetermined first temperature (for example, 25 ° C.) than the hot water supply set temperature. Is set.

  When the hot water supply set temperature is lower than the reference temperature (for example, 40 ° C.), the first temperature (for example, 25 ° C.) higher than the hot water set temperature, and the second temperature (for example, 50 ° C.) higher than the preset hot water temperature. The lower one is set as the tapping temperature.

  When the user sets the hot water supply set temperature to 38 ° C. lower than the reference temperature, for example, when the water supply temperature is 10 ° C., the temperature calculated based on the hot water supply set temperature (eg 38 ° C. + 25 ° C. = 63 ° C.) Since the temperature calculated based on the feed water temperature (for example, 10 ° C. + 50 ° C. = 60 ° C.) is lower, the temperature calculated based on the feed water temperature is set as the tapping temperature.

  Similarly, when the user sets the hot water supply set temperature to 38 ° C. lower than the reference temperature, for example, when the water supply temperature is 20 ° C., the temperature calculated based on the hot water supply set temperature (eg 38 ° C. + 25 ° C. = 63 The temperature calculated based on the hot water supply temperature (for example, 20 ° C. + 50 ° C. = 70 ° C.) is higher than the temperature calculated based on the hot water supply temperature.

  Here, the second temperature is appropriately set according to the capacities of the auxiliary heat source unit 4 and the pump 25, and is set so that the heat of the medium temperature water in the hot water storage tank 5 can be used as much as possible as preheating of the auxiliary heat source unit hot water. Can do. For example, if the auxiliary heat source unit 4 is No. 24 and the pump 25 has a maximum flow rate of 12 L / min, when the pump 25 is operated at the maximum flow rate of 12 L / min, the auxiliary heat source unit 4 maximizes the temperature of hot water. Therefore, the second temperature is set to a temperature of 50 ° C. or lower. In addition, the capability of the heat source machine which can raise 1 liter of hot and cold water by 25 ° C. per minute corresponds to No. 1.

Next, the operation and effect of the hot water storage hot water supply apparatus 1 of the present invention will be described.
The hot water storage and hot water supply device 1 can set the hot water set temperature of the auxiliary heat source unit 4 based on the relationship between the hot water set temperature and a predetermined reference temperature at the time of hot water discharge from the auxiliary heat source unit, and the hot water set temperature is higher than the reference temperature. Sets the hot water set temperature based on the hot water set temperature, and if the hot water set temperature is lower than the reference temperature, the hot water set temperature based on the hot water set temperature is compared with the hot water set temperature based on the water temperature, and the lower temperature hot water is set. Adopt set temperature.

  Therefore, when the hot water supply set temperature is lower than the reference temperature, the hot water in the hot water storage tank 5 can be supplied to the auxiliary heat source unit 4 at the maximum flow rate of the pump 25 by lowering the hot water set temperature and stored by hot water storage operation. Since the heat of the medium temperature water in the hot water storage tank 5 can be used as much as preheating of the hot water supply, it is possible to reduce the amount of gas used when the auxiliary heat source machine hot water is discharged. Further, the amount of clean water mixed by the mixing valve 16 to adjust to the hot water supply set temperature becomes small, and the hot water in the hot water storage tank heated by the auxiliary heat source device 4 can be used for maximum hot water supply.

An example in which the embodiment is partially changed will be described.
[1] When the hot water in the hot water storage tank 5 has been discharged, the three-way valve 17 is switched to the heat exchanger return passage portion side, and the heat exchanger return passage portion 32b from the water supply passage 10 via the branch passage portion 10a. It is also possible to heat the clean water passing through the auxiliary heat source unit 4.
[2] In addition, those skilled in the art can implement the present invention by adding various modifications without departing from the spirit of the present invention, and the present invention includes such modifications. is there.

DESCRIPTION OF SYMBOLS 1 Hot water storage hot water supply device 2 Hot water storage hot water supply unit 3 External heat source machine 4 Auxiliary heat source machine 5 Hot water storage tank 5a-5d Hot water storage temperature sensor 6 Hot water supply passage 7 Tank hot water supply passage 8 Auxiliary heating passage 10 Water supply passage 11 Control unit 16 Mixing valve 17 Three-way valve 18 Water supply Bypass passage 19 Water supply temperature sensor 25 Pump 26 Water proportional valve

Claims (2)

A hot water storage tank, a hot water supply passage connected to the upper portion of the hot water storage tank, a water supply passage connected to the lower portion of the hot water storage tank, and an auxiliary heat source device interposed in the hot water supply passage,
When the hot water temperature in the hot water storage tank is equal to or lower than the hot water supply set temperature, the hot water storage hot water supply device configured to reheat the hot water in the hot water supply passage with the auxiliary heat source machine,
The hot water set temperature when the hot water is reheated by the auxiliary heat source machine and discharged is set based on the hot water set temperature when the hot water set temperature is equal to or higher than a predetermined reference temperature, and the hot water set temperature is A hot water storage hot water supply apparatus configured to be set based on a water temperature in the water supply passage when the temperature is lower than the reference temperature.   When the hot water supply set temperature is lower than the reference temperature, the hot water set temperature set based on the water temperature in the water supply passage is compared with the hot water set temperature set based on the hot water set temperature. The hot water storage hot-water supply apparatus according to claim 1, wherein any one of the low-temperature hot-water supply set temperatures is set.